(a) Field of the Invention
The present invention relates to a novel gluconacetobacter strain having cellulose producing activity. Specifically, the present invention relates to a novel gluconacetobacter strain capable of producing nano-structured cellulose in a highly efficient manner.
(b) Description of the Related Art
Cellulose is one of the most abundant natural macromolecules on Earth with about 1011 ton estimated to be naturally synthesized, most of which is biosynthesized to be the structural component of cell wall fibers of higher plants. Its high tensile strength is mainly due to its overall structure. Cellulose molecules form a chain or microfibril whose length ranges to 14,000 units, which in turn is structured into a twisted rope-shaped bundle maintained by hydrogen bonds. On the basis of its characteristics of being abundant and having unique physical properties, many studies with regard to its possible industrial applicability as a regenerating resource have been performed.
Since A. J. Brown reported in 1886 that Acetobacter produced cellulose, Bacterial Cellulose (BC) produced by a microorganism has become the subject of continuous studies as a new material. In particular, it has been discovered that microorganism-derived BC forms ribbon-like bundles, whereas plant-derived cellulose forms bundles of microfibrils.
In contrast to microfibril bundles formed by plant-derived cellulose, the ribbon-like bundles formed by microorganism-derived BC are produced in their pure state in the absence of lignin or hemicelluloses. The unique advantageous characteristics of BC such as high mechanical strength, high water absorption, high crystallizability, and biodegradability promote development of its diverse applications in a variety of industrial fields.
Currently, despite its high cost, s-glass has been selected as a suitable material for substrates of liquid crystal displays (LCDs) due to its properties, including low heat expansion coefficient, high permeability, and micro-thickness. It has been reported that LCD substrate thermodynamic properties can be enhanced relative to those of s-glass by using nano-structured cellulose, which can be produced by microorganisms. (Schraamm, M. and S. Hestrin. 1054. Factors affecting production of cellulose at the air/liquid interface of a culture of Acetobacter xylinum. J. Gen. Microbiol. 11:123-129). Therefore, it is desirable as well as cost-effective to develop a microorganism that is more efficient in producing cellulose.
Although it is well-known that acetobacter xylinum can produce BC, its inefficiency in production of cellulose has called for a novel organism that can replace it.